Escapement mechanism



Feb. 9, 1960 G. DROUHOT ESCAPEMENT MECHANISM Filed July 6, 1955 9 WW pm 144M United States Patent C ESCAPEMENT MECHANISM Germaine Drouhot, La Fare-les-Oliviers, France, assignor to Lip S.A dHorlogerie, Besangon (Doub), France, a French body corporate Application July 6, 1955, Serial No. 520,340 Claims priority, application France July 12, 1954 9 Claims. (CI. 74-15) The present invention is concerned essentially with an escapement mechanism designed for adjusting and regulating in permanent fashion the angular velocity of a member rotating continuously and incorporated, for example, in a clockwork or like precision mechanism, of the type wherein this rotating member is regulated by the action of a mechanically resonant constant frequency oscillating member, the amplitudes of oscillation of which are determined by the regulated rotating member itself, the oscillating member controlling the average velocity of rotation of said rotating member with a high degree of accuracy.

Generally, escapement mechanisms of this type are frequently employed in precision chronometric devices and more particularly in clock and watch-making. Now, the various escapements with magnetic or mechanical regulators of this character have serious inconveniences which have been avoided only partly up to, now. In this respect it is appropriate to cite the galloping of the mechanism which may be due either to an overtension of the power spring, or to an excessive torque produced for example upon resetting or winding a watch or clock, this galloping of the mechanism being also caused by a loss of control by the governor of the regulator wheel on account of a shock or a jolt, or to the error of position resulting from the pendular action exerted on the vibrator, etc. However, in ordinary magnetic' or mechanical escapements the amplitude of the vibration or oscillation cannot exceed certain limits as it is regularly attended by a loss of control of the train of wheels, which cannot be tolerated in clockworks. It is impossible to suppress the galloping arising therefrom and constituting a source of misadjustment, unless the mechanism is stopped.

Now the escapement mechanism provided by the present invention makes it possible to overcome this inconvenience and is remarkable notably in that it comprises a pivotal balancing element constituting a rocker, interposed between the oscillating member and the rotating member so as to prevent any direct interaction therebetween.

It will be readily understood that the provision of an intermediate element balanced and therefore insentive to external shocks makes it possible to avoid any detrimental action thereof on the oscillating member which, under these conditions, may consist of a synchronizing rod.

Other features and advantages of the invention will appear as the following description proceeds with reference to the accompanying drawing.

In the drawing:

Figure 1 is a diagram illustrating a first form of embodiment of the invention, shown by way of example;

Figure 2 is an alternate embodiment, and

Figure 3 is another alternate embodiment.

In the example shown in Fig. l the escapement mechanism comprises a rotary member such as a disc or wheel 1to which a movement of rotation is imparted in the direction of the arrow f, for example. -In the vicinity of the periphery of this wheel there is provided a series of pins or studs 2, 3, arranged in two circular concentric rows, the pins or studs 2, 3 being disposed at regularly spaced angular intervals around the circumferences of two circles 4, 5 concentric with the rotational axis of the disc 1. The pins 2, 3 may be defined as synchronizing pins and cooperate either mechanically or magnetically with a rocker pin or magnet 6 carried by a rocker member 7 pivoted at a fixed post 8, the post 8 having fixedly inserted therein at 9 one end of an oscillating rod or reed member :10 having a free end 11. The reed member 10 is inherently tuned so that it is mechanically resonant at a predetermined frequency or flexural oscillation.

It will be readily appreciated that as the wheel 1 is rotated in the direction of the arrow 1 the pins 2, 3 spaced alternately in different circular rows or stepwise around the periphery of the wheel will act successively on the pin 6 carried by the rocker 7, thereby oscillating the latter in the direction of the arrows f and f", so that the free end 11 of reed it will oscillate correspondingly. In the example illustrated the outer surface of the rocker pivot post 8 is assumed to be coincident or aligned with an inner point at which the reed 10 becomes embedded in a notch or groove formed in the rocker; this reed member 10 may be provided, if desired, with a weight secured at its free end 11. An essential requirement is that the assembly or system of moving parts comprising the rocker member 7 and the reed member 10, when mounted as shown in the drawing, must be balanced. By providing a balanced reed and rocker system, the escapement mechanism is rendered insensitive to extraneous disturbances such as those produced by shock, building vibration or the like and direct interaction between the reed member and the rotating member is prevented, it being obvious that the reed member itself must necessarily be unbalanced.

When the rocker is provided with a metal rocker pin or element 6 of high magnetic permeability or a magnet, it will be readily understood thtat the rotating wheel will cause each of the pins 2, 3 to register successively with the rocker-carried magnet 6, thereby causing the latter to be attracted alternately by the pins 2 and 3 in two opposite directions so as to oscillate the rocker as indicated by the two arrows f and f". This oscillation is such, of course, as to sustain the oscillations of the reed member 10 and cause this vibration or oscillation to exert a controlling eliect on the velocity of travel of the pins and therefore on the angular velocity of rotation of the wheel 1.

Obviously, the rocker itself may be made of a lowdensity material so as to reduce its moment of inertia. On the other hand, a high-permeability metal pin may be substituted for the rocker-carried magnet 6, and the pins 2, 3 themselves may be magnetized. The wheel 1 may be made entirely of high-permeability metal and the pins machined or stamped from suitable stock. It may also be pointed out that the point at which the rod is embedded in or engages the rocker may differ from the location indicated in the figure, and may be positioned outside the geometrical axis thereof, if desired.

The example illustrated in Fig. 2 dilfers from the preceding one only in that the rod is independent of the rocker. In fact, the fixed end of the rod or reed member 10 is embedded at 13 in a stationary supporting block 12. Its free end 14 carries a magnet or a pin or" high magnetic permeability, co-acting with a pin or magnet 15 carried by one end of the rocker 7. The operation of this device is the same as that described hereinabove in connection with the embodiment of Fig. 1. It will be observed in Fig. 1 that the left hand end of the rocker member 7 is somewhat farther away from the supporting post 8 than its right hand end so that the rocker member 7, considered alone, is unbalanced. The unbalancing of the rocker member 7, however, is such that the systernnof moving parts consisting of therocker member '7 and the reed member 16] is a balanced system insensitive to shock and vibration. Similarly, in Fig. 2, the pin 6 is farther away from the pivot post 8 than the pin which cooperates with the end of the reed 10. Thus, a balanced system is obtained both in Fig. 1 and in Fig. 2. A shock tending to move the free end '14 of the reed id downwardly is balanced by force developed by the unbalanced rocker member 7 which tends to move the pin 15 upwardly.

The example shown in Fig.- 3 comprises a V-shaped rocker 7 having the rod embedded in its vertex and carrying a pin 6, 6" at the end of each arm 7', 7" thereof, respectively. In this specific embodiment the pins carried by the Wheel are not necessarily arranged stepwise or in two concentric alternate circular rows. A single row of pins 16 will be sufiicient, provided that their spacing and distribution are such that they act successively and alternately on the pins o, 6" so as to oscillate the rocker 7 about its pivot axis 8 in the direction of the arrows f, f. As in Fig. 1, described above, the system comprising the rocker member 7" and the reed 10 is balanced with respect to the pivotal axis of the system '7"Ilib on post 3 so that the escapement is rendered insensitive to the effects of shock and vibration, the rocker member 7 considered by itself, being unbalanced.

Of course, the invention is not limited to the specific embodiments shown and described herein, since many modifications may be made therein without departing from the spirit and scope of the invention.

What I claim is:

l. in an escapement mechanism, a driven rotary merry her the average angular velocity of which is to be regulated, pivot means spaced from and fixedly positioned with respect to the rotational axis of said rotary member,

the rotational axis of said pivot means being parallel to that of said rotary member, a reed member, means maintaining one end of said reed member fixed with respect to said pivot means, the other end of said reed member being oscillating with respect to said fixed end, said reed member being tuned to have a predetermined resonant frequency of flexural oscillation; an unbalanced rocker member supported on said pivot means for free pivotal oscillatory movement about said pivot means, said rocker member being connected to said reed member for controlled displacement therewith, said rocker member and reed member together constituting a shock and vibration resistant system balanced with respect to said pivot means; a first regulatory means carried by said rotary member; and a second regulatory means carried by said rocker member, said second regulatory means cooperating with said first regulatory means to exert a control effect on said rotary member accompanying each oscillation of said reed member, said control efiect limiting the angular velocity of said rotary member to a predetermined magnitude for each oscillation of said reed member with said rotary member supplying energy to said reed member through said cooperation of said first and second regulatory means for maintaining said reed member in a sustained oscillatory condition.

2. Escapement mechanism comprising a driven rotary member the average angular velocity of which is to be regulated, pivot means spaced from and fixedly positioned with respect to the rotational axis of saidrotary member, the rotational axis of said pivot means being parallel to that of said rotary member, a reed member,

means maintaining one end of said reed member fixed with respect to said pivot means, the other end of said reed member being oscillating With respect to said fixed end, said reed member being tuned to have a predetermined resonant frequency of flexural oscillation; an unbalanced rocker member supported for free pivotal move ment on said pivot means, said rocker member being connected to said reed member for controlled displacement therewith, said rocker member and reed member together constitutinga shock and vibration resistant system balanced about said pivot means, a series of regularly angularly spaced pins carried by said rotary member, said pins being disposed in a circular arrangement concentric with the rotational axis of said rotary member, at least one rocker pin mounted on said rocker member for cooperation with said spaced pins, said rocker pin having forces exerted thereon by successive ones of said spaced pins for displacement of said rocker member for maintaining said reed member in a sustained oscillatory condition and simultaneously exerting a control eifect on said rotary member to maintain a constant value for said average velocity.

3. Escapement mechanism according to claim 2 in which said rocker pin is of a magnetic character and wherein said regularly spaced pins are arranged in two concentric circles with alternate pins disposed at the circumference of each circle, said spaced pins being or a magnetic character and said forces being magnetic forces.

4. Escapement mechanism according to claim 2 in which said rocker member carries two spaced rocker pins, movement of said rocker member to bring one of said rocker pins into cooperative position with respect to said series of pins causing an accompanying withdrawal of the other rocker pin from said cooperative position.

5. Escapement mechanism according to claim 2, wherein said means maintaining one end of said reed member fixed is separate from and spaced from said pivot means, said escapement mechanism further comprising cooperating magnetic members carried by said movable end of said reed member and said rocker member, respectively, whereby said rocker member is magnetically connected to said reed member for displacement therewith.

6. Escapement mechanism according to claim 1, wherein said means maintaining said one end of said reed member fixed is formed integrally with said pivot means.

7. Escapement means according to claim 1, wherein said means maintaining said one end of said reed member fixed is separate and spaced from said pivot means.

8. Escapement means according to claim 2, wherein said means maintaining said one end of said reed member fixed is formed integrally with said pivot means.

9. Escapement means according to claim 2, wherein said means maintaining said one end of said reed member fixed is separate and spaced from said pivot means.

References Cited in the file of this patent UNITED STATES PATENTS 1,795,013 Denman Mar. 3, 1931 1,825,382 Baker Sept. 29, 1931 1,973,510 Schierferstein Sept. 11, 1934 2,373,429 Straumann Apr. 10, 1945 2,385,011 Lurtz Sept. 18, 1945 2,679,722 Kohlhagen June 1, 1954 2,690,646 Clifford Oct. 5, 1954 2,743,614 Cliiford May 1, 1956 

